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Biomedical subjects

R G Somes

Publications and source records attributed to R G Somes.

At least 19 recordsLinked to original sources
PubMed1988

Variability in the amino terminus of myosin light chain 1.

Three naturally occurring variants of myosin light chain 1, type I, II, and III from avian fast-twitch muscle, have been analyzed by reverse-phase HPLC peptide mapping and amino acid sequencing. Difference peptides were absent from accompanying digests of the related protein, myosin light chain 3, indicating that the heterogeneity was located in the N-terminal 50 residues unique to light chain 1. The type II variant possessed the previous published sequence for the protein [Nabeshima Y., Fujii-Kuriyama, Y., Muramatsu, M., & Ogata, K. (1984) Nature (London) 308, 333-338]. The type I variant, which migrates faster than the type II on SDS gene electrophoresis, contained a Pro----Ala substitution at residue 15, turning the Lys-Pro-(Ala)5(Pro-Ala)7 stretch in this region into Lys-Pro-(Ala)7(Pro-Ala)6. The type III variant, which migrates just faster than the type I, had an (Ala)2 deletion in the (Ala)5 run, yielding Lys-Pro-(Ala)3-(Pro-Ala)7. As indicated by the SDS gel migration rates, the type I and III variants are significantly shorter in length than the type II. The benign nature of the changes is consistent with a flexible arm function for the N-terminal region of light chain 1, with the structural changes in the variants occurring in the spacer region of the arm.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1985

Myosin light chain-1: genetic analysis of three variants found in fast white chicken muscle and investigation of linkage with the muscular dystrophy gene.

Backcross and F2 analyses have been carried out to determine the genetic basis of inheritance of three myosin light chain-1 variants present in the fast white muscle fibers of the domestic chicken. Two of the variants (types I and II) were described previously [Rushbrook, J. I., Yuan, A. I., and Stracher, A. (1982). Muscle Nerve 5:505], while the existence of the third (type III) is reported here. The results are consistent with an autosomal and allelic origin for the variants. A test linkage backcross to the muscular dystrophy gene am was found to be negative. This is the twelfth negative linkage result for the am gene.

Animals↗
PubMed1984

Sodium-ion dependence of glycine and lysine transport in chicken erythrocytes genetically selected for high and low leucine transport activity.

Amino acid transport was studied in two lines of chickens, one high and the other low uptake, selected for their ability to transport leucine into erythrocytes. On the basis of the number of mol of substrate transferred, medium Na+ was found to be more effective in stimulating glycine and lysine transport into high line cells than into low line cells. Glycine transport in both lines was stimulated by medium Na+ to a greater degree than was lysine transport. In the absence of medium Na+, glycine transport was not significantly different in the two lines. In the absence of medium Na+, lysine transport in the high line was about five-fold greater than in the low line. The transport differences between the lines are probably due to differences in several distinct genetic determinants.

Animals↗
PubMed1983

The effect of the naked neck gene, Na, on growth and carcass composition of broilers raised in two temperatures.

Eight-week-old broilers of the three genotypes, normally feathered (na+/na+), heterozygous naked neck (Na/na+), and homozygous naked neck (Na/Na), were compared for growth performance and body composition characteristics at two environmental temperatures, 21 C in the cool room and 38 C in the hot room. Birds maintained in the cool room attained significantly greater live, New York dressed, and eviscerated weights than did birds maintained in the hot room, while consuming 93% more feed and achieving 84% greater weight gain. However, there were no significant differences in feed conversion ratios. Percent yield was 3% greater for birds in the hot room. In the cool room, na+/na+ birds were heavier than Na/Na birds for body weight measurements while in the hot room the reverse was true. In both temperatures the na+/na+ and Na/na+ birds were similar. For New York dressed percent yield, the Na/Na and Na/na+ were similar and had greater yield than na+/na+ birds in the cool room. The same trend held for birds in the hot room but to a much less degree. Eviscerated yield showed no genotype X temperature interactions. Body composition data indicated that Na/Na birds contained more moisture, similar protein, less lipid (particularly in cool room), and more ash (particularly in hot room) than the na+/na+ birds. Overall, in the hot environment, the Na/Na birds achieved significantly greater body weights than na+/na+ birds while containing less lipid but more moisture and ash.

Animals↗
PubMed1983

The embryonic development of ear-tufts and associated structural head and neck abnormalities of the Araucana fowl.

Developing embryonic structural abnormalities of ear-tufted embryos of the Araucana fowl are described. These abnormal structures are peduncle, cleft, ear opening, tympanic membrane, and columella auris. The structural abnormalities are believed to be due to the early incomplete fusion of the hyoid and mandibular arches from the distal part of the ear opening to the neck area.

Animals↗
PubMed1982

Amino acid transport and intracellular Na+ and K+ content of chicken erythrocytes genetically selected for high and low leucine transport activity.

1. Amino acid transport and intracellular Na+ and K+ content have been studied in two lines of chickens, one high and the other low uptake, selected for their ability to transport leucine into erythrocytes. 2. Low line birds were less effective in absorbing glycine into erythrocytes than were high line birds, the difference in transport being due to a difference in maximal flux (Vmax), but not in apparent affinity for transport sites (Kt). 3. In contrast to glycine uptake, the greater ability of the high line to absorb lysine was found to be due to a difference in both Vmax and Kt. 4. High line erythrocytes were also observed to contain slightly more K+ (about 5%) and about 20% less Na+ than low line erythrocytes. 5. These results are discussed in terms of the ion dependency of amino acid transport.

Amino Acids↗
PubMed1982

The effect of the scaleless gene, sc, on growth performance and carcass composition of broilers.

Two experiments were conducted in which featherless broilers (scaleless, sc/sc) were compared with feathered broilers for growth and body composition characteristics at environmental temperatures of 22, 34, and 38 C. The sc gene reduces growth and efficiency at 22 C but at 38 C the sc/sc broilers gain more, eat more, and are more efficient than feathered broilers. They achieve greater live, New York dressed, and eviscerated weights and consistently have greater eviscerated yields. The sc/sc broilers have more protein and mineral content and less fat than the feathered broilers.

Animals↗
PubMed1981

Selective breeding of chickens for erythrocytes with high and low leucine transport activity.

Two lines of chickens, one high and the other low uptake, have been selected for three generations for their ability to transport leucine into erythrocytes. Significant line differences were produced in one generation of selection with further separation resulting in later generations. Selection progress has been exclusively with the high-uptake line, the low line not differing significantly from the control. The maximal rate of leucine uptake, the stimulation of leucine transport by medium Na+, lysine uptake, and the Na+-K+-ATPase activity all were greater in the high line. Rates of glucose transport were not different between the lines nor were intracellular concentrations of Na+ or K+.

Animals↗
PubMed1981

Gross morphological head and throat abnormalities of the tufted Araucana embryo.

Structural abnormalities of the head and throat of ear-tufted embryos of the Araucana fowl are described. These abnormalities involved the opening to the external auditory meatus and such bones as the mandible, quadrate, columella auris, squamosal, and hyoid apparatus. Structural irregularities are believed to be due to the presence of the Et gene and its influence on the early embryonic closure of the hyomandibular cleft. The diversity of phenotypic expression probably is due to the varied closure of the cleft.

Animals↗
PubMed1980

The mottling gene, the basis of six plumage color patterns in the domestic fowl.

The tricolored plumage patterns known as speckled, mille fleur, porcelain, and spangled (Old English Game type) were studied along with the black and white mottled plumage pattern. Crosses between birds carrying these phenotypes showed the mo gene to be common to all of these plumage color patterns. Crosses between Speckled Sussex and Black-tailed White Japanese Bantams resulted in a new plumage color pattern in which silver replaced gold to change a tricolored to a bicolored pattern. The recessiveness of the mo gene was verified by crossing birds of the wild-type plumage coloration which differed only at the mo locus. Also, a hypothesis for the gene action of mo is offered to account for the many different phenotypes produced by it.

Animals↗
PubMed1980

The effect of the Kn gene of the sexual development of cockerels.

The sexual development of cockerels of three feather growth rate genotypes, k+/k+, Kn/k+, and Kn/Kn, was studied at 2-week intervals from ages 1 to 31 weeks. Body, testis, and comb weights were collected. Histologic evaluation of testes and semen fertility tests were also made. The Kn gene, when homozygous, delayed body growth, and testis growth and development in homozygous males, thus delaying their sexual maturity 2 to 3 weeks. Body weights, relative testis weights, and seminiferous tubule diameters were similar for the k+/k+ and Kn/k+ males but significantly different from the Kn/Kn males. Stages of spermatozoic development were not significantly different between males of any of the genotypes. Regressions of relative testis weight on body weight and of seminiferous tubule size and stage of spermatozoic development on relative testis weight were not different for any of the genotypes. Relative comb size was significantly different between males of all three genotypes. When regressed against relative testis weight, the Kn/Kn males were significantly different from the other two groups of males. The Kn gene exerted an influence, directly or indirectly, which appeared to reduce testosterone production in the Kn/Kn males. The nature of the Kn gene's action was not evident from these data, nor was it clear whether it was acting on the Leydig cells of the testes or on the lutinizing hormone producing cells of the pituitary.

Animals↗
PubMed1980

The influence of the white-wing feather plumage gene Ww on various quantitative traits in chickens.

The white-wing plumage color gene Ww which acts as an embryonic lethal in homozygotes was studied to determine its pleiotropic effects on various quantitative traits. Two groups of birds Ww/ww+ and ww+/ww+ were compared for mortality, body weight, age to sexual maturity, egg production, egg weight and shape, and egg shell thickness. During 0 to 8 weeks of age, the Ww/ww+ birds showed three times greater mortality than did the ww+/ww+ birds. From 8 to 71 weeks of age their mortality was similar, although during the 36 to 71 week period the Ww/ww+ birds did show a somewhat higher level of mortality. The cause of the mortality was not determined. Body weight was consistently depressed for the Ww/ww+ birds; however, it was not always significantly so. No significant differences were noted among the other traits measured.

Animals↗
PubMed1978

Uropygial gland alkane diol diesters in the Kn mutation of the domestic chicken.

Uropygial glands from chickens which are known to have the Kn gene secrete qualitatively the same types of alkane diol diesters as the normal domestic chicken. However, there are many significant differences in the mole percent of individual fatty acids and diols within the diester between the two genetic types of chickens. In general, the mutant chickens have lesser amounts of the shorter chain fatty acids and diols and greater amounts of the longer chain fatty acids and diols. There is also a gene dosage effect with two mutant genes having a greater effect in many cases than a single mutant gene.

Animals↗
PubMed1977

Protein and cholesterol content of Araucana chicken eggs.

Comparative data collected over two years are presented which refute the popular press claims that blue-shelled eggs of Araucana chickens have higher protein levels and lower cholesterol levels than market eggs. These comparisons were made between the eggs from the strains of Araucanas and those of White Leghorns and Sex-links. None of the differences found between test groups in % protein/g. albumen and % protein/g. yolk were shown to be consistently related to any one test group type. However, all Araucana test groups were significantly (P less than .01) lower in their total egg protein content than either control group by from 2.8--6.5%. This lower total protein content was the result of a consistent increase in the yolk/albumen ratio of the Araucana eggs over the market eggs. The Araucana eggs were consistently higher in their cholesterol levels on a mg./g. yolk basis than either of the market eggs. These increased concentrattions ranged from 2.0--6.9%.

Animals↗
PubMed1975

Pleiotrophic effects of the sex-linked delayed feathering gene, K-n, in the chicken.

In several series of comparative measurement studies the effect that the sex-linked delay feathering (K-n) gene had on comb and uropygial gland development was measured in chickens from two to 60 weeks of age. The gene's effect on heart, adrenal gland and reproductive organ weights were also determined. The comb and uropygial gland size differences were very dramatic throughout the whole age range. Combs of mutant birds were greatly reduced in size while the uropygial glands were greatly hypertrophied. Heart and adrenal gland weights were also significantly increased in the mutant birds. Gonad weights however showed no difference. Responsiveness of mutant chick's combs to injections of testosterone propionate was also tested and shown to have a response similar to that of non-mutant chicks.

Adrenal Glands↗